We're Jewish!

The quote:
"We're Jewish?! That explains EVERYTHING."

The back story:
I was conceived through in vitro fertilization with an anonymous donor. I have no idea who my biological father is,and it should be noted,no desire to know who he is as a person, I just want his medical history. I had genetic testing done through 23&Me to determine what my genetic markers were. I highly recommend the site, they're not paying me or anything, I just think it's awesome. The thing about genetic testing is that to get information about your daddy, you gotta have a sample of daddy's DNA. I don't... Alas. But, it does trace all the way through your maternal line and I learned that I'm something like 17% Jewish(if that's even possible, I don't think it is, but I do have Jew blood.) When I told Mama the first thing she said was We're Jewish?! That explains Everything!" then in the same breath she said "Don't tell your grandmother!" My Grandmother is 86 and a little close minded, like steel trap rusted shut close minded, she'd be a little upset. So it's our secret. Habits and behaviors that were always just the way our family did it have become our "Jewish roots showing themselves."